Western Australia's Astronomy & Space Science Community
John asks “We are trying to work out what is the first star/planet we can see every night from Perth and is it the same star/planet every night?”
Horizon astronomer Jacquie Milner responds;
The first star or planet you can see will definitely change from season to season and year to year. It could be any of the following at any time; The planets Venus, Jupiter and occasionally Mars, or the brightest stars, such as Sirius or Canopus can all the be the first star out. Sometimes stars such as Spica in Virgo get noticed as the evening star when it is setting soon after the sun. Right now – August 2008 - you would be looking for either Venus, which has just returned to the evening sky in the west, or Jupiter, which is now high in the east at sunset. Venus can be seen in the twilight after the sun has set, low in the west. It will gradually get a bit higher over the coming months so it will get easier to see in a short while and take over from Jupiter. Venus will remain in the evening sky until early next year.After Venus has passed out of the evening sky and into the morning sky early next year, the star Sirius will take over as the evening star during Autumn in 2009. As winter sets in the title will pass to Jupiter, in the east again, just to give you an example of how different objects can take on the role of the first ‘star’ out.On Dec 1st this year we will get to see Jupiter and Venus together with the moon, which will be a beautiful sight to see! The only way to be sure of what you might be looking at or for and where to look for the ‘evening star’ is to keep a regular eye on the sky and learn a few of the brighter stars and constellations and check out where the planets are. There is a regular annual publication called “Astronomy 2008” (or whatever year it is) that I usually recommend for people where you can find easy to understand information (in picture form) on where to find the planets in the sky at any time. Most good book stores will have them or can get them (ABC stores, Dymocks etc). The publisher is Quasar publishing. Keep looking up!